Fluval Foam Filter Blocks provide effective first-stage mechanical filtration for Fluval 204/205/206 and 304/305/306 model filters. These foam blocks are custom-fit to trap large particles and debris, with an ideal pore size to allow efficient water passage and prevent clogging.
* Traps particles and debris for mechanical filtration * Pore size allows efficient water passage with less clogging * Safe for freshwater and marine aquariums * For Fluval 204/205/206 and 304/305/306 filters
The additional filter surface area provided by this foam also enhances biological filtration.